I am looking to see what everyone likes to use for an insulation layer. I am in the market for something mainly around camp but could use on the trail if conditions require it. Upcoming trip will be in the alpine. Average high 70-75 and average lows 35-45. It needs to be packable and compress small. I have a Frogg Togg for my rain/wind jacket but need something for warmth.

I have done some research and have seen a few I like, Rab Xenon X ($215) and North Face ThermoBall (~$175). Is there something similar to these that is under $100?

Any help would be great. Thanks